1. Field of the Invention
This invention concerns water clarification in general. More specifically, it deals with a system for controlling clarification of boiler water and the like.
2. Description of the Prior Art
It has been past practice to apply variable timers to make controlled procedures for drawing sludge away from a gravity water clarification system in which the removal of solids and particulates is accomplished by using chemical coagulants in the clarification process. However, with the introduction of polymers that are substituted for prior conventional chemical coagulants, the sludge removal control has become more critical largely because of the reduced volume of sludge that is produced.
Thus, it is an object of this invention to provide a system that gives variable control of the draw-off so as to adjust for variations in the volume of sludge produced.
Heretofore, there have been systems disclosed dealing with removal of turbidity from water or other liquids with solid suspensions therein, e.g., U.S. Pat. Nos. 3,262,878 to R. W. Beckley, et al, July 26, 1966 and 3,542,674, G. R. Machlan, Nov. 24, 1970. However, in those prior systems, there are filters being employed as principal elements therein. And, consequently, those systems are not particularly relevant to the applicant's invention.